$(function(){
  console.log('hello world!');
  let $btn = $('input'),
    delay = 6,
    timer = null;

  $btn.val("同意（" + delay + "s)");
  $btn.attr('disabled', 'disabled');
  timer = setInterval(() => {
    $btn.val("同意（" + --delay + "s）");
    if(delay === 0) {
      clearInterval(timer);
      $btn.val("同意");
      $btn.removeAttr('disabled');
    }
  } , 1000);
  $btn.click(() => {
    alert('button clicked!');
  })

});
